Fan control system and method

Abstract

A fan control system includes an alternative current (A/C) source, a programmable logical controller (PLC), a switch module, and a fan module. The PLC includes a detecting module. The switch module is connected to the A/C source. The fan module is connected to the switch module. The fan module includes a plurality of fans. The PLC is adapted to control the switch module thereby changing a power level output to the fan module, according to an ambient temperature of the fan module and an air pressure difference between a cold channel and a hot channel of the fan module in turn. If the pressure difference is smaller than a predefined value, the plurality of switches are switched by the PLC to provide a higher power to the fan module.

1 . A fan control method, comprising:
 controlling a level of power output of a fan module by a plurality of switches;   switching on one of the plurality of switches by sending a control signal from a programmable logical controller (PLC);   detecting an ambient temperature of the fan module and detecting an air pressure difference between a cold channel and a hot channel, wherein the fan module is communicated with the cold channel, and the cold channel is configured to input cool airflows to a heat element, and the hot channel is configured to output hot airflows from the heat element;   if an air pressure difference between the hot channel and the cold channel is smaller than a predefined value, switching the plurality of switches by the PLC to provide a higher power output to the fan module.   
     
     
         2 . The method of the  claim 1  further comprising continuing detecting the air pressure difference in a predetermined first time period after switching the plurality of switches by the PLC. 
     
     
         3 . The method of the  claim 2 , wherein the predetermined first time period is about 30 seconds. 
     
     
         4 . The method of the  claim 1  further comprising if the air pressure difference is greater than the predefined value, returning to detect the ambient temperature of the fan module. 
     
     
         5 . The method of the  claim 1 , further comprising switching the plurality of switches by the PLC, if the ambient temperature of the fan module exceeds a predetermined temperature in a predetermined second time period. 
     
     
         6 . The method of the  claim 1 , wherein the plurality of switches comprises four switches, each of the four switches being adapted to operate at a different level of power output, and only one of the four switches is switched on at a time. 
     
     
         7 . The method of the  claim 6 , further comprising operating one of the plurality of switches at a highest level of power output as an initial state of the fan module. 
     
     
         8 . The method of the  claim 7 , further comprising switching to another one of the plurality of switches at a lowest level of power output after operating the plurality of switches at the highest level of power output for about 3 minutes. 
     
     
         9 . A fan control system, comprising:
 an alternative current (A/C) source;   a programmable logical controller (PLC), comprising a detecting module;   a switch module connected to the A/C source; and   a fan module connected to the switch module, and the fan module comprising a plurality of fans,   wherein the PLC is adapted to control the switch module thereby changing a level of power output to the fan module, according to an ambient temperature of the fan module and an air pressure difference between a cold channel and a hot channel of the fan module; the fan module is communicated with the cold channel, and the cold channel is configured to input cool airflows to a heat element, and the hot channel is configured to output hot airflows from the heat element, and if the air pressure difference is smaller than a predefined value, the plurality of switches are switched by the PLC to provide a higher level of power output to the fan module.   
     
     
         10 . The fan control system of the  claim 9 , wherein the PLC is adapted to continue detecting the air pressure difference in a predetermined first time period after switching the plurality of switches to provide the higher level of power output to the fan module by the PLC. 
     
     
         11 . The fan control system of the  claim 10 , wherein the predetermined first time period is about 30 seconds. 
     
     
         12 . The fan control system of the  claim 9 , wherein the PLC continue to detect the ambient temperature of the fan module, if the air pressure difference is greater than the predefined value. 
     
     
         13 . The fan control system of the  claim 9 , wherein the PLC is further adapted to switch the plurality of switches, if the ambient temperature of the fan module exceeds a predetermined temperature in a predetermined second time period. 
     
     
         14 . The fan control system of the  claim 9 , wherein the plurality of switches comprises four switches, each of the four switched being adapted to operate at a different level of power output, and only one of the four switches is switched on at a time. 
     
     
         15 . The fan control system of the  claim 9 , wherein the PLC is further adapted to switch the plurality of switches to operate at a highest level of power output at an initial state of the fan module. 
     
     
         16 . The fan control system of the  claim 15 , wherein the PLC is further adapted to switch another one the plurality of switches to operate at an original level of power output after continuing operating the plurality of switches at the highest level of power output for about 3 minutes.